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1.
Nat Commun ; 15(1): 1038, 2024 Feb 03.
Article in English | MEDLINE | ID: mdl-38310103

ABSTRACT

There are significant commonalities among several pathologies involving fibroblasts, ranging from auto-immune diseases to fibrosis and cancer. Early steps in cancer development and progression are closely linked to fibroblast senescence and transformation into tumor-promoting cancer-associated fibroblasts (CAFs), suppressed by the androgen receptor (AR). Here, we identify ANKRD1 as a mesenchymal-specific transcriptional coregulator under direct AR negative control in human dermal fibroblasts (HDFs) and a key driver of CAF conversion, independent of cellular senescence. ANKRD1 expression in CAFs is associated with poor survival in HNSCC, lung, and cervical SCC patients, and controls a specific gene expression program of myofibroblast CAFs (my-CAFs). ANKRD1 binds to the regulatory region of my-CAF effector genes in concert with AP-1 transcription factors, and promotes c-JUN and FOS association. Targeting ANKRD1 disrupts AP-1 complex formation, reverses CAF activation, and blocks the pro-tumorigenic properties of CAFs in an orthotopic skin cancer model. ANKRD1 thus represents a target for fibroblast-directed therapy in cancer and potentially beyond.


Subject(s)
Cancer-Associated Fibroblasts , Skin Neoplasms , Humans , Cancer-Associated Fibroblasts/metabolism , Fibroblasts/metabolism , Muscle Proteins/metabolism , Nuclear Proteins/genetics , Nuclear Proteins/metabolism , Receptors, Androgen/genetics , Receptors, Androgen/metabolism , Repressor Proteins/genetics , Repressor Proteins/metabolism , Skin Neoplasms/pathology , Transcription Factor AP-1/genetics , Transcription Factor AP-1/metabolism , Tumor Microenvironment
2.
bioRxiv ; 2023 Jun 28.
Article in English | MEDLINE | ID: mdl-37425957

ABSTRACT

Alterations of nuclear structure and function, and associated impact on gene transcription, are a hallmark of cancer cells. Little is known of these alterations in Cancer-Associated Fibroblasts (CAFs), a key component of the tumor stroma. Here we show that loss of androgen receptor (AR), which triggers early steps of CAF activation in human dermal fibroblasts (HDFs), leads to nuclear membrane alterations and increased micronuclei formation, which are unlinked from induction of cellular senescence. Similar alterations occur in fully established CAFs, which are overcome by restored AR function. AR associates with nuclear lamin A/C and loss of AR results in a substantially increased lamin A/C nucleoplasmic redistribution. Mechanistically, AR functions as a bridge between lamin A/C with the protein phosphatase PPP1. In parallel with a decreased lamin-PPP1 association, AR loss results in a marked increase of lamin A/C phosphorylation at Ser 301, which is also a feature of CAFs. Phosphorylated lamin A/C at Ser 301 binds to the transcription promoter regulatory region of several CAF effector genes, which are upregulated due to the loss of AR. More directly, expression of a lamin A/C Ser301 phosphomimetic mutant alone is sufficient to convert normal fibroblasts into tumor-promoting CAFs of the myofibroblast subtype, without an impact on senescence. These findings highlight the pivotal role of the AR-lamin A/C-PPP1 axis and lamin A/C phosphorylation at Ser 301 in driving CAF activation.

3.
Nat Commun ; 14(1): 887, 2023 02 16.
Article in English | MEDLINE | ID: mdl-36797248

ABSTRACT

Epigenetic mechanisms oversee epidermal homeostasis and oncogenesis. The identification of kinases controlling these processes has direct therapeutic implications. We show that ULK3 is a nuclear kinase with elevated expression levels in squamous cell carcinomas (SCCs) arising in multiple body sites, including skin and Head/Neck. ULK3 loss by gene silencing or deletion reduces proliferation and clonogenicity of human keratinocytes and SCC-derived cells and affects transcription impinging on stem cell-related and metabolism programs. Mechanistically, ULK3 directly binds and regulates the activity of two histone arginine methyltransferases, PRMT1 and PRMT5 (PRMT1/5), with ULK3 loss compromising PRMT1/5 chromatin association to specific genes and overall methylation of histone H4, a shared target of these enzymes. These findings are of translational significance, as downmodulating ULK3 by RNA interference or locked antisense nucleic acids (LNAs) blunts the proliferation and tumorigenic potential of SCC cells and promotes differentiation in two orthotopic models of skin cancer.


Subject(s)
Arginine , Epigenome , Humans , Arginine/metabolism , Keratinocytes/metabolism , Histones/metabolism , Cell Differentiation/genetics , Protein-Arginine N-Methyltransferases/metabolism , Repressor Proteins/metabolism , Protein Serine-Threonine Kinases/metabolism
4.
Science ; 376(6590): eabh1623, 2022 04 15.
Article in English | MEDLINE | ID: mdl-35420948

ABSTRACT

Human cells produce thousands of lipids that change during cell differentiation and can vary across individual cells of the same type. However, we are only starting to characterize the function of these cell-to-cell differences in lipid composition. Here, we measured the lipidomes and transcriptomes of individual human dermal fibroblasts by coupling high-resolution mass spectrometry imaging with single-cell transcriptomics. We found that the cell-to-cell variations of specific lipid metabolic pathways contribute to the establishment of cell states involved in the organization of skin architecture. Sphingolipid composition is shown to define fibroblast subpopulations, with sphingolipid metabolic rewiring driving cell-state transitions. Therefore, cell-to-cell lipid heterogeneity affects the determination of cell states, adding a new regulatory component to the self-organization of multicellular systems.


Subject(s)
Fibroblasts , Skin , Sphingolipids , Fibroblasts/chemistry , Fibroblasts/classification , Fibroblasts/metabolism , Humans , Lipidomics/methods , Metabolic Networks and Pathways , Skin/chemistry , Skin/metabolism , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Sphingolipids/analysis , Sphingolipids/metabolism , Transcriptome
5.
Int J Environ Sci Technol (Tehran) ; 19(10): 10375-10380, 2022.
Article in English | MEDLINE | ID: mdl-34691198

ABSTRACT

This work aimed to investigate the effect of freezing on the oleuropein content obtained from olive leaves extracts. The extracts were obtained by microwave-assisted extraction using different solvents, pH, temperatures and microwave irradiation time. Afterward, HPLC was used to identify and quantify the amount of oleuropein in the extracts. A part of the extracts was immediately analyzed, and another was frozen for a week. The experimental results highlighted that the storage condition has a significant (p < 0.05) effect on the oleuropein content. Regardless of the extraction condition, the frozen storage was responsible for a decrease in the oleuropein content, ranging from 5.38 to 70.09%. These results indicate that it is important to consider the degradation of oleuropein in frozen olive leaf extracts so that subsequent applications are suitable.

6.
EMBO Rep ; 22(3): e52152, 2021 03 03.
Article in English | MEDLINE | ID: mdl-33554445

ABSTRACT

"Flash forward genetics" refers to a genetic approach based on the functional interaction of a given factor with unknown partner(s) converging on shared targets across evolutionary boundaries. A study by Li et al (2021), published in this issue of EMBO Reports, illustrates the innovative potential of the approach. The authors applied it to identify interacting factors for FOXN1, a mammalian transcription factor with a highly specialized function in hair follicle morphogenesis and thymus. The authors express FOXN1 in the Drosophila eye to perform an unbiased genetic screen in a totally heterologous system. In a remarkable tour de force, the authors identify and characterize a factor so far known for its ubiquitous function in transcription elongation, AFF4. Li et al show that AFF4 plays also a specific role in hair follicle and thymus development in the mouse overlapping with that of FOXN1.


Subject(s)
Forkhead Transcription Factors , Hair Follicle , Animals , Biological Evolution , Forkhead Transcription Factors/genetics , Forkhead Transcription Factors/metabolism , Gene Expression Regulation , Hair Follicle/metabolism , Mice , Mice, Nude
7.
Chemosphere ; 269: 128748, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33139043

ABSTRACT

Two new adsorbents, namely avocado-based hydrochar and LDH/bone-based biochar, were developed, characterized, and applied for adsorbing 2-nitrophenol. The pore volume and surface diffusion model (PVSDM) was numerically solved for different geometries and applied to interpret the adsorption decay curves. Both adsorbents presented interesting textural and physicochemical characteristics, which achieved maximum adsorption capacities of 761 mg/g for biochar and 562 mg/g for hydrochar. The adsorption equilibrium data were well fitted by Henry isotherm. Besides, thermodynamic investigation revealed endothermic adsorption with the occurrence of electrostatic interactions. PVSDM predicted the adsorption decay curves for different adsorbent geometries at different initial concentrations of 2-nitrophenol. The surface diffusion was the main intraparticle mass transport mechanism. Furthermore, the external mass transfer and surface diffusion coefficients increased with the increase of 2-nitrophenol concentration.


Subject(s)
Water Pollutants, Chemical , Adsorption , Charcoal , Hydrogen-Ion Concentration , Kinetics , Nitrophenols , Solutions , Thermodynamics
8.
J Exp Med ; 218(2)2021 02 01.
Article in English | MEDLINE | ID: mdl-33112375

ABSTRACT

Melanoma susceptibility differs significantly in male versus female populations. Low levels of androgen receptor (AR) in melanocytes of the two sexes are accompanied by heterogeneous expression at various stages of the disease. Irrespective of expression levels, genetic and pharmacological suppression of AR activity in melanoma cells blunts proliferation and induces senescence, while increased AR expression or activation exert opposite effects. AR down-modulation elicits a shared gene expression signature associated with better patient survival, related to interferon and cytokine signaling and DNA damage/repair. AR loss leads to dsDNA breakage, cytoplasmic leakage, and STING activation, with AR anchoring the DNA repair proteins Ku70/Ku80 to RNA Pol II and preventing RNA Pol II-associated DNA damage. AR down-modulation or pharmacological inhibition suppresses melanomagenesis, with increased intratumoral infiltration of macrophages and, in an immune-competent mouse model, cytotoxic T cells. AR provides an attractive target for improved management of melanoma independent of patient sex.


Subject(s)
Carcinogenesis/genetics , Cell Proliferation/genetics , Melanoma/genetics , Receptors, Androgen/genetics , Signal Transduction/genetics , Animals , Carcinogenesis/pathology , Cell Line, Tumor , DNA Damage/genetics , DNA Repair/genetics , Down-Regulation/genetics , Female , Gene Expression Regulation, Neoplastic/genetics , Humans , Male , Melanoma/pathology , Mice , Mice, Inbred C57BL , Mice, Inbred NOD , Mice, SCID , RNA Polymerase II/genetics
9.
Nat Commun ; 11(1): 5126, 2020 10 12.
Article in English | MEDLINE | ID: mdl-33046701

ABSTRACT

Cancer associated fibroblasts (CAFs) are a key component of the tumor microenvironment. Genomic alterations in these cells remain a point of contention. We report that CAFs from skin squamous cell carcinomas (SCCs) display chromosomal alterations, with heterogeneous NOTCH1 gene amplification and overexpression that also occur, to a lesser extent, in dermal fibroblasts of apparently unaffected skin. The fraction of the latter cells harboring NOTCH1 amplification is expanded by chronic UVA exposure, to which CAFs are resistant. The advantage conferred by NOTCH1 amplification and overexpression can be explained by NOTCH1 ability to block the DNA damage response (DDR) and ensuing growth arrest through suppression of ATM-FOXO3a association and downstream signaling cascade. In an orthotopic model of skin SCC, genetic or pharmacological inhibition of NOTCH1 activity suppresses cancer/stromal cells expansion. Here we show that NOTCH1 gene amplification and increased expression in CAFs are an attractive target for stroma-focused anti-cancer intervention.


Subject(s)
Cancer-Associated Fibroblasts/metabolism , Gene Amplification , Receptor, Notch1/metabolism , Skin Neoplasms/metabolism , Animals , DNA Damage , Female , Forkhead Box Protein O3/genetics , Forkhead Box Protein O3/metabolism , Humans , Mice , Mice, SCID , Receptor, Notch1/genetics , Skin/metabolism , Skin Neoplasms/genetics
10.
Chemosphere ; 250: 126248, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32092573

ABSTRACT

Medium density fiberboard (MDF) wastes were converted into an efficient char able to uptake Food Red 17 dye (FR17) from colored effluents. The yield of the pyrolysis process, in terms of char, was 29%. The produced char presented micro and mesoporous, with surface area of 218.8 m2 g-1 and total pore volume of 0.122 cm3 g-1. Regarding to the FR17 adsorption, removal percentages of 90% were found at pH 2 and using 0.5 g L-1 of char. Pseudo-first and pseudo-second order models were adequate to represent the adsorption kinetic profile, being the equilibrium reached within 20 min. Freundlich model was selected to represent the equilibrium data. The maximum adsorption capacity was 210 mg g-1. The adsorption of FR17 on the char was endothermic and physical in nature. The char was efficient for 8 adsorption-desorption cycles, maintaining the same adsorption capacity. In brief, this work demonstrated a useful practice in terms of cleaner production. It was possible add value to MDF wastes, generating an efficient and reusable adsorbent to treat colored effluents containing FR 17 dye.


Subject(s)
Azo Compounds/chemistry , Water Pollutants, Chemical/chemistry , Water Purification/methods , Adsorption , Coloring Agents , Hydrogen-Ion Concentration , Kinetics , Pyrolysis , Water , Water Pollutants, Chemical/analysis
11.
EMBO Rep ; 21(2): e49924, 2020 02 05.
Article in English | MEDLINE | ID: mdl-31930672

ABSTRACT

In times of fake news, post-truths and post-science, the principles of science can inform all kinds of inquiries into the true nature of reality.

12.
J Colloid Interface Sci ; 560: 722-729, 2020 Feb 15.
Article in English | MEDLINE | ID: mdl-31706654

ABSTRACT

Chitosan-based hybrid hydrogels such as chitosan hydrogel (CH), chitosan hydrogel with activated carbon (CH-AC), scaffold-chitosan hydrogel (SCH), scaffold-chitosan hydrogel with activated carbon (SCH-AC) and scaffold-chitosan hydrogel with carbon nanotubes (SCH-CN) were synthesized, characterized and applied to adsorb Acid Blue 9 (AB) and Allura Red AC (AR) from single and simultaneous binary liquid systems. Experimental results revealed competitive adsorption as the adsorption capacity was reduced in binary system for each dye. In addition, SCH-CN presented the highest adsorption capacity for both dyes, indicating that the modification increased the number of active sites and the functionalization with OH groups favored the interactions with sulfonated groups of the dyes. A predictive artificial neural network (ANN) was implemented to forecast the adsorption capacity for AB and AR dyes as a function of initial molar concentration of each dye, adsorption time, porosity and mass percentage of carbonaceous material on each hydrogel. The network was trained with the Levenberg-Marquardt back-propagation optimization, and according to the high correlation coefficient (R = 0.9987) and low values of root mean square error (RMSE = 0.0119), sum of the absolute error (SAE = 0.7541) and sum of squares error (SSE = 0.0132), the best topology was found to be 5-10-10-10-2. The ANN proved to be effective in predicting dye adsorption capacity of each hydrogel, even for the competitive adsorption, as the R values were close to unity for all simulation systems.


Subject(s)
Azo Compounds/chemistry , Benzenesulfonates/chemistry , Chitosan/chemistry , Coloring Agents/chemistry , Hydrogels/chemistry , Nanotubes, Carbon/chemistry , Neural Networks, Computer , Adsorption , Binding, Competitive , Charcoal/chemistry
13.
Ann Oncol ; 30(12): 1914-1924, 2019 12 01.
Article in English | MEDLINE | ID: mdl-31613312

ABSTRACT

BACKGROUND: The importance of sex and gender as modulators of disease biology and treatment outcomes is well known in other disciplines of medicine, such as cardiology, but remains an undervalued issue in oncology. Considering the increasing evidence for their relevance, European Society for Medical Oncology decided to address this topic and organized a multidisciplinary workshop in Lausanne, Switzerland, on 30 November and 1 December 2018. DESIGN: Twenty invited faculty members and 40 selected physicians/scientists participated. Relevant content was presented by faculty members on the basis of a literature review conducted by each speaker. Following a moderated consensus session, the final consensus statements are reported here. RESULTS: Clinically relevant sex differences include tumour biology, immune system activity, body composition and drug disposition and effects. The main differences between male and female cells are sex chromosomes and the level of sexual hormones they are exposed to. They influence both local and systemic determinants of carcinogenesis. Their effect on carcinogenesis in non-reproductive organs is largely unknown. Recent evidence also suggests differences in tumour biology and molecular markers. Regarding body composition, the difference in metabolically active, fat-free body mass is one of the most prominent: in a man and a woman of equal weight and height, it accounts for 80% of the man's and 65% of the woman's body mass, and is not taken into account in body-surface area based dosing of chemotherapy. CONCLUSION: Sex differences in cancer biology and treatment deserve more attention and systematic investigation. Interventional clinical trials evaluating sex-specific dosing regimens are necessary to improve the balance between efficacy and toxicity for drugs with significant pharmacokinetic differences. Especially in diseases or disease subgroups with significant differences in epidemiology or outcomes, men and women with non-sex-related cancers should be considered as biologically distinct groups of patients, for whom specific treatment approaches merit consideration.


Subject(s)
Medical Oncology/trends , Neoplasms/epidemiology , Neoplasms/therapy , Sex Characteristics , Body Composition , Decision Making , Female , Humans , Male , Neoplasms/genetics , Neoplasms/pathology , Physicians , Treatment Outcome
14.
Cell Rep ; 28(9): 2358-2372.e6, 2019 08 27.
Article in English | MEDLINE | ID: mdl-31461652

ABSTRACT

Heterogeneity of cancer-associated fibroblasts (CAFs) can result from activation of distinct signaling pathways. We show that in primary human dermal fibroblasts (HDFs), fibroblast growth factor (FGF) and transforming growth factor ß (TGF-ß) signaling oppositely modulate multiple CAF effector genes. Genetic abrogation or pharmacological inhibition of either pathway results in induction of genes responsive to the other, with the ETV1 transcription factor mediating the FGF effects. Duality of FGF/TGF-ß signaling and differential ETV1 expression occur in multiple CAF strains and fibroblasts of desmoplastic versus non-desmoplastic skin squamous cell carcinomas (SCCs). Functionally, HDFs with opposite TGF-ß versus FGF modulation converge on promoting cancer cell proliferation. However, HDFs with increased TGF-ß signaling enhance invasive properties and epithelial-mesenchymal transition (EMT) of SCC cells, whereas HDFs with increased FGF signaling promote macrophage infiltration. The findings point to a duality of FGF versus TGF-ß signaling in distinct CAF populations that promote cancer development through modulation of different processes.


Subject(s)
Cancer-Associated Fibroblasts/metabolism , Carcinoma, Squamous Cell/metabolism , DNA-Binding Proteins/metabolism , Fibroblast Growth Factors/metabolism , Signal Transduction , Skin Neoplasms/metabolism , Transcription Factors/metabolism , Transforming Growth Factor beta/metabolism , Animals , Carcinoma, Squamous Cell/pathology , Cells, Cultured , Child, Preschool , Epithelial-Mesenchymal Transition , Female , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Inbred NOD , Skin Neoplasms/pathology
15.
Nat Commun ; 10(1): 3884, 2019 08 29.
Article in English | MEDLINE | ID: mdl-31467287

ABSTRACT

Genomic instability is a hallmark of cancer. Whether it also occurs in Cancer Associated Fibroblasts (CAFs) remains to be carefully investigated. Loss of CSL/RBP-Jκ, the effector of canonical NOTCH signaling with intrinsic transcription repressive function, causes conversion of dermal fibroblasts into CAFs. Here, we find that CSL down-modulation triggers DNA damage, telomere loss and chromosome end fusions that also occur in skin Squamous Cell Carcinoma (SCC)-associated CAFs, in which CSL is decreased. Separately from its role in transcription, we show that CSL is part of a multiprotein telomere protective complex, binding directly and with high affinity to telomeric DNA as well as to UPF1 and Ku70/Ku80 proteins and being required for their telomere association. Taken together, the findings point to a central role of CSL in telomere homeostasis with important implications for genomic instability of cancer stromal cells and beyond.


Subject(s)
Cancer-Associated Fibroblasts/metabolism , Carcinoma, Squamous Cell/metabolism , Fibroblasts/metabolism , Genomic Instability , Immunoglobulin J Recombination Signal Sequence-Binding Protein/genetics , Immunoglobulin J Recombination Signal Sequence-Binding Protein/metabolism , Telomere/metabolism , Carcinoma, Squamous Cell/genetics , DNA Damage , DNA-Binding Proteins , Gene Expression Regulation, Neoplastic , Gene Knockdown Techniques , HEK293 Cells , Homeostasis , Humans , Ku Autoantigen/metabolism , Membrane Proteins , Molecular Docking Simulation , Mutagenesis , RNA Helicases/metabolism , Receptors, Notch/metabolism , Signal Transduction , Skin/metabolism , Skin Neoplasms/genetics , Skin Neoplasms/metabolism , Trans-Activators/metabolism
17.
Autophagy ; 15(4): 738-739, 2019 04.
Article in English | MEDLINE | ID: mdl-30653445

ABSTRACT

In the tumor stroma, cancer-associated fibroblasts (CAFs) affect all aspects of tumor evolution. Whereas several programs leading to CAF activation have been elucidated, little is known about the impact of the microenvironment on the turnover of key CAF regulators. RBPJ/CSL is a transcriptional repressor that mediates NOTCH signaling and its down-modulation activates the gene expression program(s) leading to stromal senescence and CAF activation. We overview our evidence that conditions increasing macroautophagy/autophagy, as often found in the stroma of tumors, cause the down-modulation of the RBPJ protein. This event requires the autophagic machinery and is functionally relevant because it is associated with an increase of CAF effector gene expression. The mechanism involves the direct association with the autophagy receptor SQSTM1/p62, which is required for RBPJ down-modulation. As a reflection of increased autophagy in the stroma, both the RBPJ and SQSTM1 proteins are down-modulated in Squamous Cell Carcinoma (SCC) patient-derived CAFs. Increasing RBPJ cellular levels stabilizes SQSTM1 and down-modulates the autophagic process. Our findings identify an autophagy-initiated mechanism for RBPJ down-modulation leading to increased CAF gene expression.


Subject(s)
Autophagy , Cancer-Associated Fibroblasts , Carcinoma, Squamous Cell , Fibroblasts , Humans , Signal Transduction , Tumor Microenvironment
18.
Prog Biophys Mol Biol ; 141: 60-71, 2019 01.
Article in English | MEDLINE | ID: mdl-30055187

ABSTRACT

In this work, agro-wastes coming from soursop (peel, seeds and pulp fiber) and sugarcane (bagasse) are used as low-cost biosorbents to remove methylene blue (MB) from aqueous media. Batch experiments are performed under different experimental conditions investigating the effects of biosorbent amount, dye concentration and stirring rate. The best results were found using soursop wastes for a MB concentration of 100 mg L-1, using 0.75 g of residue and a stirring rate of 110 rpm, removing a percentage above 90%. Theoretically, adsorption kinetic can be successfully described by the pseudo-second order model. Redlich-Peterson and Sips models are adopted to interpret the equilibrium adsorption of MB on sugarcane bagasse and soursop residue, respectively. Interestingly, the monolayer model with single energy derived by statistical physics theory is also applied for a deeper explanation of the adsorption mechanism of MB on both the adsorbents. The application of this model allows defining the adsorption geometry of the investigated adsorbate and provides important information about the interactions between the adsorbate and sorbents. In particular, the modelling analysis by statistical physics allows defining that the dye molecules are adsorbed in vertical position and the adsorption process is multi-molecular (i.e. n > 1). Finally, the estimation of adsorption energy suggested that MB adsorption on biosorbent is a physisorption process.


Subject(s)
Agriculture , Cellulose/chemistry , Environmental Pollutants/chemistry , Industrial Waste , Methylene Blue/chemistry , Models, Chemical , Adsorption , Environmental Pollutants/isolation & purification , Kinetics , Methylene Blue/isolation & purification , Saccharum/chemistry
19.
J Clin Invest ; 128(12): 5531-5548, 2018 12 03.
Article in English | MEDLINE | ID: mdl-30395538

ABSTRACT

The aging-associated increase of cancer risk is linked with stromal fibroblast senescence and concomitant cancer-associated fibroblast (CAF) activation. Surprisingly little is known about the role of androgen receptor (AR) signaling in this context. We have found downmodulated AR expression in dermal fibroblasts underlying premalignant skin cancer lesions (actinic keratoses and dysplastic nevi) as well as in CAFs from the 3 major skin cancer types, squamous cell carcinomas (SCCs), basal cell carcinomas, and melanomas. Functionally, decreased AR expression in primary human dermal fibroblasts (HDFs) from multiple individuals induced early steps of CAF activation, and in an orthotopic skin cancer model, AR loss in HDFs enhanced tumorigenicity of SCC and melanoma cells. Forming a complex, AR converged with CSL/RBP-Jκ in transcriptional repression of key CAF effector genes. AR and CSL were positive determinants of each other's expression, with BET inhibitors, which counteract the effects of decreased CSL, restoring AR expression and activity in CAFs. Increased AR expression in these cells overcame the consequences of CSL loss and was by itself sufficient to block the growth and tumor-enhancing effects of CAFs on neighboring cancer cells. As such, the findings establish AR as a target for stroma-focused cancer chemoprevention and treatment.


Subject(s)
Cancer-Associated Fibroblasts/metabolism , Neoplasm Proteins/metabolism , Receptors, Androgen/metabolism , Repressor Proteins/metabolism , Skin Neoplasms/metabolism , Transcriptional Activation , Animals , Cancer-Associated Fibroblasts/pathology , Cell Line, Tumor , Female , Humans , Mice , Mice, Inbred NOD , Neoplasm Proteins/genetics , Receptors, Androgen/genetics , Repressor Proteins/genetics , Skin Neoplasms/genetics , Skin Neoplasms/pathology
20.
Cell Rep ; 24(12): 3108-3114.e4, 2018 09 18.
Article in English | MEDLINE | ID: mdl-30231994

ABSTRACT

Cancer-associated fibroblasts (CAFs) are important at all tumor stages. CSL/RBPJκ suppresses the gene expression program leading to CAF activation and associated metabolic reprogramming, as well as autophagy. Little is known about CSL protein turnover, especially in the tumor microenvironment. We report that, in human dermal fibroblasts (HDFs), conditions inducing autophagy-often found in tumor stroma-down-regulate CSL protein levels but do not affect its mRNA levels. Genetic or pharmacologic targeting of the autophagic machinery blocks CSL down-modulation. Mechanistically, endogenous CSL associates with the autophagy and signaling adaptor p62/SQSTM1, which is required for CSL down-modulation by autophagy. This is functionally significant, because both CSL and p62 levels are lower in skin cancer-derived CAFs, in which autophagy is increased. Increasing cellular CSL levels stabilizes p62 and down-modulates the autophagic process. We reveal here an autophagy-initiated mechanism for CSL down-modulation, which could be targeted for stroma-focused cancer prevention and treatment.


Subject(s)
Autophagy , Immunoglobulin J Recombination Signal Sequence-Binding Protein/metabolism , Sequestosome-1 Protein/metabolism , Skin Neoplasms/metabolism , Animals , Cell Line , Cells, Cultured , Down-Regulation , Fibroblasts/metabolism , Humans , Immunoglobulin J Recombination Signal Sequence-Binding Protein/genetics , Mice , Protein Binding , Protein Stability , Sequestosome-1 Protein/genetics , Signal Transduction
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